Expansible fluid rotary engine

ABSTRACT

The engine comprises a two lobed housing having an epitrochoidal inner surface in which is mounted a triangular rotor on an eccentric carried by a central driven shaft, the rotor and epitrochoidal surfaces forming variable volume working chambers. In one form, inlet and exhaust valves are disposed in the housing on opposite sides of the cusps of the epitrochoidal surfaces. A timing mechanism oscillates the valves between open and closed positions to respectively admit expansible fluid into the chambers to rotate the rotor and to exhaust the expanded fluid from the chambers. The valves in their closed positions have surfaces conforming to the lobe surfaces to permit the apex portions of the rotor to sweep past the valves without breaking the seal between adjacent chambers. The valves are timed by a plurality of cam shafts coupled to the driven shaft. The rotor can be driven in the reverse direction. In another form, rotary valves are utilized to admit expansible fluid into the chambers, such valves opening through the epitrochoidal surfaces. Exhaust ports opening through the end wall may be employed with either rotary or oscillatory valves. In a further form, rotary valves can be disposed for admitting fluid through the end walls of the housing.

United States Patent [191 George, Jr.

1 1 EXPANSIBLE FLUID ROTARY ENGINE [76] Inventor: Leslie C. George, Jr., 1412 Milan St.,

New Orleans, La. 70115 [22] Filed: Oct. 20, 1971 [211 Appl. No.: 190,831

Related US. Application Data [63] Continuationin-part of Scr. No. 839,012, July 3,

1969, Pat. No. 3,628,899.

Primary Examiner-Carlton R. Croyle Assistant Examiner.lohn J. Vrablik AttorneyRobert E. Le Blanc et a1.

57 ABSTRACT The engine comprises a two lobed housing having an epitrochoidal inner surface in which is mounted a triangular rotor on an eccentric carried by a central driven shaft, the rotor and epitrochoidal surfaces forming variable volume working chambers. In one form, inlet and exhaust valves are disposed in the housing on opposite sides of the cusps of the epitrochoidal surfaces. A timing mechanism oscillates the valves between open and closed positions to respectively admit expansible fluid into the chambers to rotate the rotor and to exhaust the expanded fluid from the chambersv The valves in their closed positions have surfaces conforming to the lobe surfaces to permit the apex portions of the rotor to sweep past the valves without breaking the seal between adjacent chambers. The valves are timed by a plurality of cam shafts coupled to the driven shaft. The rotor can be driven in the reverse direction. In another form, rotary valves are utilized to admit expansible fluid into the chambers, such valves opening through the epitrochoidal surfaces. Exhaust ports opening through the end wall may be employed with either to tary or oscillatory valves. in a further form, rotary valves can be disposed for admitting fluid through the end walls of the housing.

14 Claims, 24 Drawing Figures PATENTEU GET 2 I975 SHEET 10F 5 PATENEED 2 3,762,842

SHEET 5 [IF 5 HO. I2

iii

EXPANSIBLE FLUID ROTARY ENGINE This application is a continuation-in-part of application Ser. No. 839,012, filed July 3, 1969 now U.S. Pat. No. 3,628,899.

The present invention relates to a rotary engine and particularly relates to a fluid expansible rotary engine of the type mounting a rotor within an epitrochoidally shaped multi-lobed housing.

Rotary engines of the type having a multi-lobed epitrochoidal outer housing and inner rotor having a plurality of apices equal to one more in number than the number of lobes with the rotor and housing forming variable volume working chambers have been previously proposed and constructed for use as internal combustion engines and are commonly known as Wankel engines. ln such engines having a generally triangular rotor with three apiees and rotatable in a two lobed eiptrochoidal housing, there is usually a suction stroke, a compression stroke, an expansion stroke and a discharge stroke, with the shaft making three revolutions for every complete revolution of the rotor. One of the problems associated with internal rotary combustion engines of this type resides in the fact that the inlet and exhaust ports lie in communication with one another at the end of the exhaust stroke and at the beginning of the suction stroke. This overlap causes considerable dilution of the exhaust residuals with consequent reduction in efficiency. Moreover, engines of this type commonly provide apex seals which bear against the surfaces of the epitrochoidal housing. The wear rate on the seals has been extremely high. This has limited the speed and size of the engine. Another disadvantage of these internal combustion rotary engines is the lack of efficient cooling mechanism. The heat, for the most part generated by the combustion gases, is removed through the seals which are naturally small in size and make limited contact with any coolant which could be provided in the engine housing. Lubrication is also a major problem and lubrication oil consumption is high as it is burned and lost.

A rotary engine of the type having a rotor rotatable on an eccentric and within an epitrochoidal shaped housing, however, has many distinct advantages over the common internal combustion engine by virtue of its unique geometry and configuration. The present invention therefore provides a rotary engine of this geometry and configuration for use with an expansible fluid, such as steam, freon and the like. To provide such expansible fluid rotary engine, inlet and exhaust valves or ports are required and are provided. Operation of these valves requires a controlled opening and closing of these valves such that the expansible fluid can be admitted into the variable volume working chambers between the rotor and the epitrochoidal housing, expandedto drive the rotor, and exhausted. Specifically, the inlet valve must be opened at the end of an exhaust stroke to admit the expansible fluid into a working chamber and then closed to permit the fluid to expand and drive the rotor. The exhaust valve must be timed to open at the end of the expansion stroke and then closed prior to complete evacuation of the exhaust vapors to insure recompression equal to the pressure of the incoming pressure fluid. Additionally, the apex portions of the rotor must make continuous sealing contact with the surfaces of the epitrochoidal chamber to avoid leakage between adjacent chambers. To applicants knowledge, an expansible fluid rotary engine of this type employing valves which do not break the seal between the rotor and surface of the chamber has not heretofore been proposed or constructed.

To accomplish the foregoing, the present invention provides a rotary engine having the previously described geometry and configuration and including, in one form hereof, cylindrically shaped oscillating inlet and exhaust valves having slots extending diametrically therethrough. In the open position of each inlet valve, the slot provides communication between an associated variable volume working chamber and a source of expansible fluid under pressure. ln the valve open position of each exhaust valve, the slot provides communication between the working chamber containing the expanded fluid and reservoir. Portions of the valves, when open, extend through the chamber surface and project into the working chamber. In order to permit the apex seals on the rotor to sweep about the epitrochoidal surface without breaking the seal between adjacent chambers, an arcuate axially extending cutout is formed in the cylindrical surface of the valve to correspond and conform to the shape of lobed surface of the epitrochoidal shaped housing. The cutout is circumferentially spaced from the slot about the cylindrical valve member. ln this fashion, the valve can be rotated to a closed position with the arcuate cutout forming an unbroken continuation of the surface of the epitrochoidal chamber whereby the apex seals on the rotor sweep past the arcuate portion without leakage between adjacent chambers.

A timing mechanism is provided to oscillate the cylindrical valves between open and closed positions whereby the expansible fluid can be admitted and exhausted in synchronism with the rotor cycle. To this end, camshafts coupled to the engine output or driven shaft carry cam surfaces which cooperate with push rods, which, in turn, engage spring biased levers carried by the cylindrical valves whereby the axial displacement of the push rods cause the levers to oscillate the valves between open and closed positions.

As a further feature hereof, the period for fluid admission is adjustable to facilitate engine starting. To this end, the cam surface on the camshaft is cut away at an angle. By axially displacing the camshaft, the cam surface is selectively positioned to a greater or lesser circumferential extent below the push rod associated with the inlet valve whereby the inlet valve may be held open for a selected period of time.

It is a further feature ofthe present invention that the engine can be run in the reverse direction. To accomplish this, each of the camshafts carries a pair of cam surfaces. For operating the engine in one direction, the camshafts are axially displaced such that one of the cam surfaces is engageable with the push rods operating the associated inlet or exhaust valves in a manner to permit operation in one direction. By axially displacing the camshafts to locate the second cam surface below the associated push rods, the timing of the valves can be reversed to permit rotation of the rotor in the opposite rotary direction. That is to say, the valves employed as inlet and exhaust valves for rotating the rotor in one direction can be employed as exhaust and inlet valves respectively for rotating the rotor in the opposite direction.

In another form hereof, exhaust ports are provided opening through the end walls of the housing. The rotor sequentially covers and uncovers the exhaust ports as it rotates about the epitrochoidal cavity. Particularly, when the rotor uncovers the exhaust port with the latter opening into a variable volume working chamber between the rotor surface and the lobe surface, the expanded fluid is exhausted through the port to a reservoir. Upon movement of the rotor such that the rotor covers and seals the exhaust port, the fluid may be admitted and expanded in the working chamber.

In a still further form of the present invention, cylindrically shaped rotary inlet valves are employed. In an embodiment thereof, the rotary valve includes a sleeve rotatable about a shaft fixed to the engine housing. The shaft has a radial slot in communication through a central bore in the shaft with a source of fluid under pressure. The sleeve has a pair of diametrically opposed slots. Also, an arcuate surface having a radius slightly smaller than the radius of the epitrochoidal surface is provided adjacent each of the slots in the sleeve. Timing gears connected between the output shaft and the sleeve unidirectionally rotate the sleeve such. that the sleeve and shaft slots are selectively aligned and misaligned to respectively admit fluid into the chamber and seal the chamber from fluid admission. The timing gears and sleeve are arranged such that the arcuate surface on the sleeve is exposed in the cavity when the apex seals on the rotor sweep past the valve position. Particularly, the timing is such that the leading edge of the arcuate surface lies flush with the trailing edge of the lobe surface adjacent the sleeve when an apex seal makes the transition from the lobe surface onto the valve surface. As the apex seal sweeps over the arcuate surface and back onto the lobe surface on the other side of the sleeve, the sleeve continuously rotates such that the apex seal and arcuate surface on the sleeve form a continuous seal between adjacent working chambers.

To ensure a smooth transition of the apex seals as they pass either the rotary or oscillatory fluid admission valves opening through the inner periphery of the epitrochoidal surface, guides are provided on opposite sides of the valves. That is, the valve sleeves are formed to a width less than the width of the rotor. Guides are located on opposite sides of the valve sleeves and form continuations of the epitrochoidal surfaces for a distance at least as great as' the peripheral extent of the valves along the lobe surface. These guides provide supporting surfaces against which the apex seals engage as they traverse the valve sleeves, the apex seals also sealingly engaging with the supporting surfaces. The epitrochoidal surface configuration of these guide surfaces'precludeany stepping action of the apex seals as they move onto and off of the arcuate surfaces of the valve sleeves and hence any intercommunication of adjacent variable volume chambers.

A rotary type valve may also be disposed to admit fluid into the variable volume chambers through an end wall of the motor housing. Specifically, a timing gear is connected between the output shaft and a sleeve. The sleeve has a passage in communication at one end with a source of fluid under pressure. The opposite end of the passage is offset from the sleeve axis. When the sleeve is rotated, the offset passage is sequentially placed in communication with the variable volume working chamber and sealed against the side face of the housing to respectively admit fluid into the working chamber and seal the chamber from fluid admission.

Accordingly, it is a primary object of the present invention to provide a novel, improved expansible fluid rotary engine.

It is another object of the present invention to provide a novel, improved expansible fluid rotary engine of the type having a multi-lobed epitrochoidal housing mounting a rotor having multiple apiccs one more in number than the number of lobes.

It is still another object of the present invention to provide an expansible fluid rotary engine having inlet and exhaust valves conforming in the closed position to the inner surfaces of the epitrochoidally shaped rotor housing to preclude leaking between adjacent variable volume working chambers.

It is a further object of the present invention to provide an expansible fluid rotary engine having inlet and exhaust valves having surfaces conforming to the epitrochoidally shaped surface together with a timing mechanism for locating such surfaces as to permit passage of the apex seals thereby without breaking the seal between adjacent working chambers.

It is a related object of the present invention to provide an expansible fluid rotary engine having oscillatory fluid admission and/or exhaust valves.

It is a further related object of the present invention to provide an expansible fluid rotary engine wherein exhaust ports are provided in the end walls of the housing for exhausting the expanded fluid from the variable volume chambers.

It is a still further related object of the present invention to provide an expansible fluid rotary engine of the type having a multi-lobed epitrochoidal housing mounting a rotor having multiple apices one more in number than the number of lobes with rotary fluid admission valves either in combination with like exhaust valves or exhaust valves opening through the end walls of the motor housing.

It is a still further related object of the present invention to provide an expansible fluid rotary engine of the type having a multi-lobed epitrochoidal housing mounting a rotor having multiple apiccs one more in number than the number of lobes with either rotary or oscillatory fluid admission valves opening through the periphery of the epitrochoidal surface and having surfaces adjacent the admission valves for guiding and supporting the apex seals as they pass over the valves.

It is a still further object of the present invention to provide an expansible fluid reversible rotary engine.

It is a still further object of the present invention to provide an expansible fluid rotary engine of the type mounting a rotor for rotation within an epitrochoidally shaped housing and having valves for admitting fluid under pressure into the working chambers and exhausting expanded fluid from the chambers wherein the period of fluid admission can be selectively controlled particularly to facilitate engine starting as well as vary the expansion period for maximum efficiency.

These and further objects and advantages of the present invention will become more apparent upon reference to the following specification, appended claims and drawings, wherein:

FIG. I is a cross sectional view of an expansible fluid rotary engine constructed in accordance with the present invention;

FIG. 2 is across sectional view thereof taken generally about on line 2-2 in FIG. I;

FIGS. 3a3d are reduced cross sectional views similar to FIG. 1 illustrating the rotor in various operating positions;

FIG. 4 is an end elevational view of a timing mechanism employed with the expansible fluid rotary engine hereof;

FIG. 5 is a fragmentary elevational view of a timing camshaft employed with the engine hereof;

FIG. 5a is a schematic illustration of an expansible fluid circuit for operating the engine in a reverse direction;

FIG. 6 is a schematic end elevational view ofa further form of timing mechanism employed with the engine hereof;

FIG. 7 is a fragmentary elevational view of the timing mechanism illustrated in FIG. 6;

FIG. 8 is a cross sectional view of an expansible fluid rotary engine constructed in accordance with the present invention and having a mixed pressure operation;

FIGS. 9a-9d are reduced cross sectional views similar to FIGS. 3a-3d illustrating the relative positions of the rotor and end wall exhaust ports in another form of the invention hereof;

FIG. 10a is an enlarged fragmentary view illustrating a rotary fluid admission valve constructed in accordance with another form of the present invention;

FIG. 10b is an enlarged fragmentary view illustrating an oscillatory fluid admission valve constructed in accordance with another form of the present invention;

FIG. 11 is a reduced cross sectional view thereof taken about on line ll1l in FIG. 10 and illustrating the valve in a closed position;

FIG. 12 is a view similar to FIG. 11 illustrating the timing mechanism for the rotary fluid inlet valve and the latter in an open position;

FIG. 12a is a cross-sectional view thereof taken about on line 12a-12a in FIG. 12;

FIG. 13 is an enlarged fragmentary cross sectional view of the motor housing illustrating a fluid admission valve opening through the end wall of the motor housing as well as the timing mechanism for the valve; and

FIGS. 14 and 15 are fragmentary cross sectional views of the valve mechanism illustrated in FIG. 13 and taken about on lines l4-14 and l5l5 in FIGS. 13 and 14, respectively.

Referring now to the drawings, particularly to FIG. 1, there is illustrated, in a cross section transverse to the engine axis, a trochoidal type rotary engine, generally designated 10, having an outer body comprising a two lobed peripheral housing 12 with a basically epitrochoidal inner surface 14 defining lobes 14a and 14b and a pair of end walls 16 and 18 as seen in FIG. 2. A shaft 20 extends longitudinally through the engine housing 10 and is suitably journalled in end walls 16 and 18. Shaft 20 carries an eccentric portion 22 which is received in a rotor 24, the eccentric 22 serving as a crank as the rotor 24 rotates. Suitable gear teeth, not shown, on the rotor and housing are provided whereby the rotor 24 transmits its rotary motion about the offset axis 26 of eccentric 22 thereby to rotate shaft 20 as in conventional engines having the foregoing configuration. Rotor 24 is generally triangular in outline as viewed in an axial direction having three apex portions 30a, 30b and 300, each carrying an apex seal 32a, 32b and 32c. The seals .32 of rotor 24 defined, with portions of the inner epitrochoidal surfaces 14 and the arcuate surface 34A, 34B and 34C of the rotor 24 three variable volume working chambers A, B and C. Cutout portions 36 are recessed from each of the surfaces 34 for the transfer of expansible fluid across the cusps of the epitrochoidal shaped chamber. The housing 12 may be formed of a casting or the like.

To provide for operation as an expansible fluid engine and in one form hereof, a plurality of longitudinally extending bores 38 are formed through housing 12. A pair of bores 38 are provided on opposite sides of each epitrochoidal surface 14 and on opposite sides of each cusp. The bores 38 are formed such that portions of their peripheries open through the surfaces 14a and 14b of the epitrochoidal chamber and form slots therein. Longitudinally extending reduced diameter bores or passages 40 are also formed through housing 12, outwardly of and in communication with bores 38. A pair of cylindrical expansible fluid inlet valves 42] and 44I are provided in diametrically opposed bores 38 and a pair of similar cylindrical exhaust valves 46B and 48E are provided in the other pair of diametrically opposed bores 38. Thus, an inlet and an exhaust valve are provided on opposite sides of each of the cusps. Each of the valves 42I, 44I, 46E and 48E is provided with a through diametrically extending slot 50. Valves 421, 441, 46E and 48E are suitably mounted for rotation in end walls 16 and 18 and are provided with suitable seals, indicated at 52 in FIG. 2. It will be appreciated that the passages 40 and the slots 50 are arranged such that when the valves 42I, 44I, 46E and 48E are rotated to positions wherein the slots 50 open into chambers A, B and C, the opposite ends of the slots open into the axially extending cylindrical passages. The passages 40 associated with the inlet valves 42I and 44I communicate through an aperture, not shown, in end wall 16 with a source of expansible fluid under pressure. The passages 40 associated with the exhaust valves 46E and 48E communicate through an aperture 54, as seen in FIG. 2, formed in end wall 16, the aperture 54 preferably communicating with a fluid reservoir, not shown. Accordingly, when the valves 42I and 46E are disposed in the positions illustrated in FIG. 1, expansible fluid under pressure is admitted from passage 40 through the slot 50 in valve 421 into working chamber A, while the expansible fluid in working chamber B is exhausted therefrom through the slot 50 in valve 46E into its associated passage 40. It will be appreciated that communication through these valves to their associated passages '40 is precluded when they are rotated to valve positions exemplified by the positions of closed valves 44l and 48E in FIG. 1.

As described hereinafter in detail, rotor 24 rotates within the epitrochoidal chamber with the seals 32 sweeping along the epitrochoidal surfaces 14a and 14b in continuous sealing engagement therewith. Each seal 32 is disposed in a recess 61 formed in the associated apex portions 30 of the rotor 29 and comprises, as seen in FIG. 2, an elongated strip including a main body formed of a very lightweight metal and having a tip 62 formed of a plastic material such as nylon or teflon. The tip material provides a wearing surface bearing against the inner walls 14a and 14b of the epitrochoidal chamber. As seen in FIG. 2, a plurality of helical springs 64 are located between each seal strip and the base of its associated recess 6H whereby seal strips 32 are biased outwardly into constant sealing engagement with the epitrochoidal surfaces 14a and 14.

As the rotor seals 32 must lie in continuous contact with the surfaces of the epitrochoidal chamber as the rotor rotates within the housing 12, it is essential that the contour of the chamber remain unbroken as otherwise the seals would be ineffective to preclude communication between adjacent working chambers. It is, accordingly, a particular feature of the present invention that the valves 42I, 44I, 46E and 48E are specifically configured such that, when these valves lie in a valve closed position, they form with the adjacent epitrochoidal surfaces 14a and 14!: a smooth, continuous and unbroken surface. This permits the apex seals to remain in sealing engagement with the walls of the epitrochoidal'chamber even as the seals sweep past the valves. To this end, each of the cylindrical valve members 42I, 44], 46B and 48E is provided with an arcuate cutout portion 66 extending axially along its periphery and corresponding in curvature to and forming a continuation of the curvature of the associated epitrochoidal surfaces 14a and 14b. Thus, surfaces 66 complement the epitrochoidal surfaces 14a and 14b when the valves are disposed in a closed position, i.e., the valves 44I and 488 in FIG. 1, whereby the apex seals 62 remain in constant sealing engagement along the surfaces 14a and 141; as they sweep past the slots accommodating the valves and formed through the chamber wall.

The movement of rotor 24 within the chamber and the timed movement of the valves will now be described the timing mechanism for the valves being described hereinafter. When the rotor 24 lies in the position illustrated in FIG. 3a, valves 42l and 46B are open and valves 44] and 485 are closed. Valve 42! accordingly admits expansible fluid under pressure from associated passage 40 into chamber A, the latter being defined between the rotor surface 34A and the wall portions of surfaces 140 and 14b between apex seals 32a and 32c. Valve 46B is open permitting chamber B to exhaust through the valve into its associated passage 40, chamber B being defined between the rotor surface 34b and the wall portions of surfaces 14a and 14!; between the apex seals 32a and 32b. Valves 44I and 48B have just closed and the chamber C defined by rotor surface 34c and the portion of surfaces 140 and 1417 between apex seals 32b and 320 contains expansible fluid admitted from its associated passage 40 when valve 44] was open. The fluid in chamber C expands to drive rotor 23 in a counterclockwise direction thereby also driving output shaft 20 in a counterclockwise direction. When the rotor has advanced to the position illustrated in FIG. 3b, the-period of fluid admission in chamber A is complete and the valve 42I has rotated to a closed position. Note that, in the movement of rotor 24 from the position illustrated in FIG. 3a to the position illustrated in FIG. 3b, the apex seal 32c has swept past the arcuate surface 66 of valve 48E and seal 32b bears on the surface 66 of valve 44], each without breaking its sealing engagement with the wall of the epitrochoidal chamber. The valve 46E remains in the open position exhausting chamber B. The valve 48E has rotated to an open position exhausting chamber C. In this rotor position, rotor 24 is driven by the expansion of the fluid in chamber A with the rotor obtaining the position illustrated in FIG. 3c. In this position, the valve 46E has rotated to a closed position and the valve 44I has rotated to an open position to admit fluid into chamber B. Chamber C continues to exhaust the fluid through the open valve 48E. The expansion in chamber A continues to rotate rotor 24 in a counterclockwise direction. In FIG. 3d, the apex seal 32a has swept past the valve 46E and the latter has rotated to an open position to exhaust the expansible fluid from chamber A into its associated exhaust passage 40. The valve 44] has rotated to the illustrated closed position with the period of admission of expansible fluid into chamber B being complete. The valve 48E remains open and continues to exhaust the fluid from chamber C. The rotor has thus advanced 90 from the rotor position of FIG. 3a to the rotor position illustrated in FIG. 3d. It will be noted that as soon as fluid expansion in one of the chambers is complete and begins to exhaust, expansion in a second chamber is initiated and power is thereby continuously provided for rotating the rotor.

It will be appreciated that cylindrical valves 42I, 44I, 46B and 48E oscillate about their longitudinal axes between positions admitting fluid into and exhausting fluid from the working chambers and positions wherein the arcuate surfaces 66 continuations of epitrochoidal surfaces 140 and 14b. To obtain this oscillatory motion in a timed sequence, i.e., to open and close the valves at the proper points in the operating cycle, a timing mechanism is provided and illustrated in FIGS. 4 and S. In FIG. 4, the cylindrical valves extend through the end wall 18 of the engine housing and carry lever arms 70. Springs 72 engage between lugs 74 fixed to the engine housing and the lever arms thereby biasing the valves into normally closed positions. Levers 70 bear against adjusting screws 76 in the valve closed positions. Push rods 78 are slidably carried by the housing and engage the ends of associated levers 70, the opposite ends of push rods 78 carrying rollers 77 for hearing against associated camshafts 80. Each camshaft 80 mounts a pair of projecting cams 82a and 82b at axially spaced positions therealong. The camshafts 80a associated with inlet valves 42] and 44I carry cams 82a and 82!) as illustrated in FIG. 5, while the camshafts 80b associated with the. exhaust valves 46B and 48E carry cams 82a and 82b in an axially reversed position, not shown. That is to say, each cam 82a on camshafts 80b is located in the position occupied by cam 82b in FIG. 5 while each cam 82b on camshafts 80b is located in the position occupied by cam 82a in FIG. 5. Cams 82a and 82b are normally associated with the inlet and exhaust valves respectively. The camshafts 80 are slidably carried by the engine housing, by means not shown, and carry sprockets 94 splined to the camshafts 80. An external portion of the driven shaft 20 mounts a similar sprocket 86 in FIG. 4 and a drive chain 88 connects between the drive sprocket 86 and the driven sprocket 84. A chain drive 87 emcompasses the four sprockets 84 whereby the camshafts are driven in a timed relation to the driven shaft 20.

As seen in FIG. 5, the cams 820 are substantially triangular in shape having a base surface portion 89 and a hypotenuse surface 90 for reasons noted hereinafter. Thus, as the respective camshafts 80a rotate, the rollers 77 on the end of push rods 78 associated with the inlet valves engage cams 82a and ride up base surfaces 89 and over the cams to displace the push rods. This, in turn, displaces levers 70 thereby pivoting the associated inlet valve. As the camshafts 80a continue to rotate, the rollers on push rods 78 drop off the cam surfaces 90 back onto the camshafts 80a whereby springs 72 pivot levers 70 and the associated valves in the opposite direction into the normally closed valve positions. It will be appreciated that the Camshafts 80b and earns 82b associated with the exhaust valves operate in a like manner with the cams 82b similarly causing displacement of the associated rods and levers corresponding oscillation of the exhaust valves is effected. It will, of course, be appreciated that the camshafts are initially positioned such that the cams are disposed in various circumferential positions in relation to the associated push rods whereby the proper timing cycle is effected.

To vary the period of admission of expansible fluid into the working chambers through the valves 421 and 441, as for example, to provide an increase period of admission during the initial starting of the engine, cams 82a are triangular in shape, as previously described. Thus, by axially shifting the cams 82a with respect to the push rods 78, the period in which the cams 82a displace the push rods and hence maintain the inlet valves in an open position can be varied. To this end, and for reasons set forth below, .each of the camshafts 80 is axially displaceable by means of a pivoted actuating lever 92 which has a yoke portion 94 engageable with a collar 96 carried on camshaft 80. The opposite end of the lever 92 is selectively reciprocated by means of a fluid actuated cylinder 98. Accordingly, to extend the period of admission, the fluid actuated piston is extended to pivot lever 92 in a clockwise direction as seen in FIG. thereby to displace camshaft 80 to the right. By thus displacing camschaft 80, a circumferentially greater surface of cam 82a is disposed below roller 77 whereby the associated inlet valve is maintained in an open position for an extended period of time. This is particularly desirable during starting in order to give the engine maximum starting torque with the period of admission being curtailed or shortened by axially displacing the camshaft 80 to the left as seen in FIG. 5 as the rotor begins to turn. It will be further appreciated that by displacing the camshaft 80a to the left such that the cam 82a lies beyond the roller 77, the inlet valves would be maintained in their normally closed positions whereby the engine would stop. The cams 82b associated with the exhaust valves are rectangular in shape about camshafts 80 whereby axial displacement of the latter to vary the period of admission has no effeet on the period during which the exhaust valves remain open. It will be appreciated that the cylinders 98 can be operated, as by suitable valving; now shown, to jointly advance and retract the camshafts 80. It will also be appreciated that the period of exhaust could be varied in like manner. For example, the cam 82b can be shaped such that the exhaust valve could be closed sooner or later, as desired.

By providing inlet and exhaust valves of approximately the same size, the engine can be operated such that the rotor rotates in a reverse direction. To accomplish this, each camshaft 80 is shifted axially in a like direction such that the cam surfaces 82a underlying the push rods 78 associated with the inlet valves and the cam surfaces 82b, underlying the push rods 78 normally associated with the exhaust valves, are moved to inoperative positions with the cams 82a on shafts 80b and the cams 82b on shafts 80a being moved to positions underlying the push rods 78. In this manner, the timing action for the valves would be reversed, that is, the valves 421 and 441 become the exhaust valves and the valves 4613 and 48E become the expansible fluid admission valves. Suitable valving, for example, the

valving arrangement shown in FIG. 5a, is provided to provide the expansible fluid under pressure to thc passages 40 associated with valves 46B and 48E and to exhaust the fluid from the passages 40 associated with the valves 421 and 441. In FIG. 5a, a closed cycle operation is shown with the expansible fluid source being indicated at S. The supply and exhaust conduits indicated at 911 and 92 respectively communicate through a fourway two-position valve 95. In the illustrated valve position, the fluid is supplied through valve to the valves 421 and 441 via passages 40 and conduit 97. The exhaust fluid is returned to the source S via passage 99 from the valves 4615 and 48E. By shifting valve 95 to the left as seen in FIG. 5a, the fluid is supplied to the valves 46E and 48E via conduit 99 and the exhaust fluid is returned to the source S via conduit 97. In this manner, the expansible fluid can be selectively provided to valves 421, 441 or 46E, 48E as desired with the expanded fluid being returned through the other set of valves. Thus, simply by axially shifting the camshafts 80 and shifting valve 95, the engine can be run such that the rotor rotates in either direction.

The foregoing timing arrangement has been described with respect to a four camshaft arrangement with one camshaft operating each valve. With reference to FIGS. 6 and 7, it will be seen that the timing arrangement can be accomplished with two camshafts. To this end, a pair of triangularly shaped cams 82a and 82a are spaced along a single camshaft 100. Similarly, a pair of cam surfaces 82b and 82b are spaced one from the other between the cam surfaces 82a and 82a. It will be appreciated that, in this form, the levers 78 associated with the inlet and exhaust valves on each side of the engine housing are axially offset one from the other such that the roller 77 associated with the push rod of the inlet valves rides on the cam surface 82a and roller 77 associated with the push rod 78 of the exhaust valve rides on the cam surface 82b.

The position of the camshaft illustrated in FIG. 7 corresponds to the position of the rotor 24 illustrated in FIG. 3a. That is to say, the inlet valve 421 is open as it has been pivoted by the displacement of push rod 78 riding on the cam 82a. As seen in FIG. '7, the push rod 78 associated with the exhaust 48E rides on camshaft 100 whereby the valve lies in its normally closed position. Upon further rotation of the camshaft 100, the cam 82a rotates beyond lever 78a whereby the spring 72 biases lever 70 against screw 76 thereby to pivot inlet valve cylinder 421 back to its normally closed position illustrated in FIG. 3b. Simultaneously, the cam surface 821; will have rotated to a position below the push rod 78 associated with valve 48E to thereby open the valve as illustrated in FIG. 3b. A camshaft 100 of this type is provided on each side of the engine housing.

As in the camshaft arrangement illustrated in FIG. 5, the camshafts 100 of the embodiments of FIGS. 6 and 7 can be axially displaced to both alter the period of admission of expansible fluid into the working chambers as previously described and also to reverse the function of the admission and exhaust valves, i.e., to operate the admission valves 421 and 441 as exhaust valves and to operate the exhaust valves 4615 and 48E as admission valves thereby to reverse the engine. This is accomplished by axially displacing both camshafts 100 to the left as seen in FIG. 7 such that the left hand push rod '78 engages the cam 82b and the other right hand push rod 78 engages the cam 82a. Expansible fluid is then provided the passages 40 associated with valves 46E and 48E by shifting the valve 95 as previously described. Thus, in both timing mechanisms, the camshafts can be axially shifted to both alter the period of admission and to reverse the engine.

It will be appreciated of course that a suitable interlock, not shown, can be provided between the valve 95 and the camshaft action such that the one cannot be actuated without the other.

It is a specific feature hereof that the expansible fluid rotary engine hereof can also be employed as a mixed pressure engine. That is to say, expansible fluid at two different pressures from two different sources, can be utilized simultaneously in the same engine. To accomplish this and referring now to FIG. 8, there is provided two additional valves, an inlet valve 1101 and an inlet valve 1121 lying closely adjacent and beyond the inlet valves 421 and 441, respectively. These valves are identical in construction to the valves previously described and include diametrically extending slots 50 and arcuate surface portions 66 conforming to the walls of the epitrochoidal chamber. The passages 40 associated with valves 1 101 and 1121 lie in communication with an expansible fluid source, not shown, at a pressure lower than the pressure of the fluid supplied to the passages 40 associated with inlet valves 421 and 441. The valves 1101 and 1121 are timed such that they remain in a closed position when the high pressure expansible fluid in the chambers defined in part by the arcuate surfaces 60 of the valves 1101 and 1121 is expanding after having been admitted through the valves 421 and 441 respectively. That is to say, the valves 1101 and 1121 are maintained in a closed position while the high pressure fluid is first admitted into the associated working chamber as previously described. The high pressure fluid inlet valve is then'closed by the previously described timing mechanism. When the pressure in the working chamher is reduced to a pressure substantially equal to or less than that of the lower pressure expansible fluid in passage 40, the valve 1101 or 1121, as the case may be, opens to admit the lower pressure expansible fluid and then immediately closes. In this fashion, the expansible fluid in the chamber will continue to expand and rotate rotor 24 in a like direction as in the previous embodiments. The timing mechanism for the valves 1101 and 1121 can be identical to the single camshaft timing devices illustrated in FIG. 5. The cams associated with mixed pressure operating camshafts are reduced in circumferential extent in comparison with the cam surfaces 82a whereby the period of admission for the lower pressure inlet valves 1 101 and 1121 would be substantially reduced.

A further feature of the present invention provides for ready inspection and replacement of the apex seals at the apex portions of the rotor when necessary without dismantling the engine. As noted previously, the wear on these seals is much less than the wear associated with apex seals in internal combustion engines. However, over long periods of engine operation, the seals should be replaced. To this end, a plurality of end covers 120, seen in FIG. 2, are provided about end wall 16 and suitably secure thereto by bolts 122. These end covers may be formed of metal, for example, the same metal comprising the end walls, and sealed to the engine housing, for example, by neoprene seals. To inspect the apex seals, the covers are removed and the rotor turned until the seals line up with the inspection openings. A tapped hole 124 is provided in the end of the apex seals whereby a bolt or screw can be threaded into the tapped hole and the seal including the springs withdrawn from apex recesses 61. Thus, the seals can be inspected and replaced without dismantling the end pieces or plates.

Should the rotor stop in a position wherein the fluid inlet valves are fully closed, as illustrated in FIG. 3b, the engine could not be started. To start the engine, a compound rotor comprising a pair of rotors on a common shaft can be provided, as schematically illustrated in FIG. 3d. The rotors are angularly offset one from the other, preferably at 60, whereby at least one of the inlet valves of one of the rotors would lie in a position to admit fluid into the working chamber and thereby drive the compounded rotor assembly.

There is illustrated in FIGS. 9a-9d another form of expansible fluid engine hereof. Particularly, there is provided a housing 120 having a cavity defined by a two-lobed epitrochoidal surface 14a and 14b and a pair of end walls, one of which is illustrated at 18a. A rotor 24a is disposed in the cavity. A shaft 20a extends longitudinally through housing 12a and is journalled in the end walls. Shaft 20a, rotor 24a, and housing 12a are similar in all respects with the corresponding parts previously described in the embodiment hereof illustrated in FIG. 1 with the exception of the exhaust valves. Also, inlet valves 421 and 441' are disposed and operate similarly as the valves 421 and 441 are disposed and operated in FIG. 1.11! this form, however, instead of exhaust valves opening through the epitrochoidal peripheral surface of housing 12a as in the previous embodiment, the exhaust valves comprise ports opening through one or both of the end walls, FIGS. 9a-9d illustrating the exhaust ports 100 and 102 opening through end wall 18a. The ports 100 and 102 are located in end wall 18a in communication with the cavity portions defined by lobes 14a and 14b, respectively. The expanded fluid in the working chambers thus exhausts through the ports when the rotor 24a uncovers the ports during its rotary excursion and is precluded from exhausting when the rotor 24a covers the ports. The rotor is provided with side seals, not shown, about the margin of its end face to seal the exhaust ports from the working chambers when the rotor covers the ports.

When rotor 24a lies in the position illustrated in FIG. 9a, valve 421 and port 100 are open and valve 441' and port 102 are closed. It will be appreciated that the side seals on the end face of rotor 24a preclude communication between the ports 100 and 102 on the one hand and the working chambers on the other hand when the rotor 24a completely covers the exhaust port, for example, port 102 in FIG. 9a, through the end wall 18a. Valve 421', in this rotor position, is admitting expansible fluid under pressure from the associated passage 40' into chamber A. Chamber B is exhausting through port 100 to a reservoir, not shown. Valve 441 has just closed and the fluid in chamber C is expanding. Valve port 102 is covered by rotor 24a and hence sealed from chambers A, B and C. When rotor 240 has advanced to the position illustrated in FIG. 91) through the expansion of fluid in chamber C, valve 431' remains open admitting additional fluid into chamber A. However,

rotor 24 a has moved to a position partially closing exhaust port and partially opening exhaust port 102. Upon further movement of rotor 24a into the position illustrated in FIG. 90, valve 421' is closed and the fluid in chamber A expands to drive the rotor. The fluid in chamber B is very nearly completely exhausted through exhaust port 100 while the expanded fluid in chamber C continues to exhaust through the full open exhaust port 102. [Valve 44I remains closed with the apex seal passing over its arcuate surface thereof in the manner previously described] Upon rotation of rotor 24a into the position illustrated in FIG. 9d, the fluid in chamber A is substantially fully expanded and continues to drive the rotor. Also, exhaust port 100 is now completely covered whereby the fluid remaining in chamber B recompresses prior to opening admission valve 441 to obtain a pressure approximating the fluid inlet pressure. Upon slight further rotation of rotor 24a and obtaining a comparable pressure in chamber B as the fluid admission pressure, valve 44l opens in a manner previously'described to permit fluid into chamber B in FIG. 9d. The expanded fluid in chamber C fully exhausts through the now fully open exhaust port 102. The cycle continues as previously described and as will be apparent with the fluid being admitted through inlet valve 44I' and exhausting through the end wall port 102.

It will be noted that the location in the end wall 18a of the exhaust ports 100 and 102, as well as their contour, will determine the point in the cycle at which the ports will be covered by the rotor and recompression will begin. Since it is desirable that the recompression pressure be brought up to the pressure of the inlet fluid, the pressure desired will be determined by the exhaust pressure and the position of the exhaust port in the end wall. A.fluid system similar to the fluid system illustrated in FIG. a is utilized to supply fluid to and exhaust fluid from valves 42I', 44l' and ports 100, 102, respectively.

It will be appreciated that in the foregoing description, the oscillatory valves 42I' and 44I' are utilized as inlet valves while the ports 100 and 102 in the end wall or walls are utilized as exhaust ports. The engine hereof, however, can be run in a reverse direction, that is, clockwise as illustrated in FIGS. 9a-9d. The timing cam shafts are shifted axially as previously described. Where a fluid system similar to the system illustrated in FIG. 5a is used, a reversing valve, for example the valve 95 illustrated in FIG. 5a, is shifted to supply fluid to the ports 100 and 102 and connect the valves 42I' and 44I' to the fluid exhaust to thereby drive the rotor in a reverse clockwise direction. The timing is such that when the rotor successively covers the inlet ports 100 and 102, the fluid in the adjacent chambers expands to drive the rotor, the fluid being thereafter exhausted by opening the respective valves 42I and 441' only after the inlet ports 100 and 102 are sealed from such chambers. That is, the timing is such in the embodiment that, whenever a valve 42] and 441 is open to exhaust, the ports 100 and 102 are sealed from the chamber exhausting through the open valve by either being covered by the rotor face or by an apex seal to preclude vapor blow-by. To control the speed of the engine during reversing, a throttle valve is provided in the exhaust line, for example as illustrated at 101 in FIG. 50.

Referring now to FIGS. l0-12,,there is illustrated a rotary valve useful in the expansible fluid rotary engine hereof. The rotary valve comprises a sleeve 110 closed at one end 112 (FIG. 12) and suitably journalled in the end walls 16b and 18b of the engine housing. Sleeve 110 includes a pair of diametrically opposed slots 114 and 116 which, as illustrated in FIG. 12, sequentially open into the working chambers within the epitrochoidal cavity upon rotation of sleeve 110. Adjacent each slot 114 and 116 and formed on the outer surface of sleeve 110 are arcuate surfaces 118 and 120 having a radius slightly smaller than the radius of the epitrochoidal cavity at the location of the valve for reasons as will become apparent. Contained within sleeve 110 is a fixed shaft 121 having a central bore 122 and a radial slot 124 opening in the general direction of the epitrochoidal cavity. It will be appreciated that as sleeve 110 rotates relative to shaft 120, the slots 114 and 116 are successively aligned with the slot 124. In this manner, fluid under pressure contained within bore 122 and provided from a suitable fluid pressure source, not shown, flows through slot 124 and the slot 114 or 116 which lies in registry therewith for admitting fluid into the working chamber.

External to the motor housing, there is provided a gear 126 (FIG. 12) carried by sleeve 110 and which gear 126 meshes with a gear 128 fixed on shaft 20b. Shaft 20b is, in turn, driven by rotor 24b. Thus, rotation of sleeve 110 is timed with the rotation of output shaft 20b such that fluid is admitted into the working chamber at the appropriate times in the working cycle. Particularly, gear 126 is continuously driven by gear 128 from output shaft 20b. Consequently, sleeve 110 rotates continuously. When one of the slots, for example slot 116, rotates into a position in registry with slot 124, fluid is admitted into the working chamber. As sleeve 110 continues to rotate, slot 116 passes over center with respect to slot 124 and the slots become misaligned with respect to one another thereby preventing communication between bore 122 and the working chamber. Upon further rotation of sleeve 110, arcuate surface 120 is exposed through the epitrochoidal surface into the working chamber The timing is such that the leading edge 130 of arcuate surface 120 and the trailing edge 132 of the epitrochoidal surface lie flush one with the other at a point in the cycle when an apex seal makes the transition from the lobe surface to the arcuate surface 120. As the apex seal passes over the arcuate surface 120, the sleeve continues to rotate such that continuous and sealing contact is maintained between the apex seal and the arcuate surface 120. When the apex seal makes the transition from the arcuate surface back to the lobe surface, the trailing edge 134 of the arcuate surface 120 lies flush with the leading edge 136 of the lobe surface due to the continuous rotation of valve sleeve 110. Since the peripheral speed of the rotor is greater than the peripheral speed of the sleeve, a smaller radius is provided arcuate surface 120 than the lobe surface. This ensures continuous sealing engagement between the apex sealand the arcuate surface as they rotate at different speeds and maintains the working chambers completely sealed one from the other as the apex seals pass over the valves.

It is desirable to prevent the vapor from striking the trailing edge 132 and leading edge 136 of the epitrochoidal surface as this might wear or erode these sur faces. The openings 114, 116 and 124 are thus sized and located such that vapor flow starts and ends only when the openings 114 and 116 are spaced from the trailing and leading edges 132 and 136 respectively.

It will be appreciated that the end wall exhaust ports such as illustrated in the embodiments of FIGS. 9a-9d can be utilized with either the oscillatory inlet valves or the rotary type inlet valves.

To guide and support the apex seals as they pass the valves, and to further ensure continuous engagement between the apex seals and the valve surfaces, the valves are provided with guide surfaces which form continuations of the epitrochoidal surfaces of the lobes. Such guide surfaces may be utilized with either the rotary or oscillatory type valves, and while the following description discusses the guide surfaces in relation to the rotary valves, it will be appreciated that the guide surfaces can also be utilized with oscillatory type valves. Referring now to FIGS. 11 and 12, the guide surfaces 140 and 142 are provided along opposite marginal portions of the inner peripheral surface of the outer body. Particularly, the openings for the valves through the inner surface of the outer body are formed to a width less than the width of the rotor. The guide surfaces 140 and 142 are provided in the areas between the openings and the walls of the rotor housing. The guide surfaces 140 and 142 may be integrally formed with the housing or may be formed separately of a suitable material, for example, teflon. The guide surfaces 140 and 142 have a circumferential extent greater than the circumferential extent of the valve opening through the inner periphery of the outer body and form continuations of the epitrochoidal shaped lobes. Thus,'the

apex seals on the rotor sweep past the valve positions in continuous engagement with the guide surfaces 140 and 142 with the latter assisting in the prevention of any stepping action when the apex seal makes the transition from the lobe surface onto the arcuate surface and from the arcuate surface back to the lobe surface. Thus, continuous sealing engagement between the apex seals on the one hand and the valves and hosuing on the other hand is maintained as the rotor apices sweep past the valve positions.

Referring now to FIG. b, a similar type of end wall fluid admission may be provided in oscillatory type valves similar to the valves 421 and 441 in the embodiment hereof illustrated in FIG. 1.' In this form, oscilla tory valve 131 comprises a sleeve 133 closed at one end and suitably journalled in the end walls of the engine housing. Sleeve 133 includes a slot 135. Adjacent slot 135 and formed on the outersurface of sleeve 133 is an arcuate surface 137 conforming to the surface contour of the epitrochoidal cavity simlarly as the surfaces 66 in FIG. 1 conform to the surface of the cavity. Contained within sleeve 133 is a fixed shaft 139 having a central bore 141 and a radial slot 143 opening in the general direction of the epitrochoidal cavity. As sleeve 133 oscillates relative to shaft 139, slot 135 is alternately aligned with slot 143 and, when misaligned, the arcuate surface 137 is exposed in the epitrochoidal cavity. When the slots are aligned, fluid under pressure contained within bore 141 flows through the aligned slots into the working chamber. It will thus be appreciated that, in this form of oscillatory valve, flow of vapor into the working chamber does not occur until the slots are in alignment and that such alignment does not occur until the slot 135 is located between the edges of the epitrochoidal cavity. Thus, the edges of the cavity cannot be eroded or abraded by the incoming vapor. Increased engine life is accordingly provided.

To ensure that the apex seals on the rotor do not catch or snag or unduly wear the juncture of the engine housing and the arcuate valve surfaces in contact with the apex seal, for example, the surface 66 in FIG. 1, surface 118 in FIG. 10a or surface 137 in FIG. 10b, the

edges defining the opening through the epitrochoidal surface into the working chamber and the edges defining these arcuate valve surfaces may extend at an angle across the epitrochoidal housing whereby the apex seal to edge contact is a point-to-point contact rather than an edge-to-edge contact. That is, the edges defining the arcuate valve surfaces and the edges of the housing which conform thereto may extend obliquely across the housing in non-parallel relation to the apex seal to define an angle with the apex seal which extends transversely across the housing. The contact between the apex seal and housing and valve edges is thus point-topoint. The edges of the housing defining the opening into the cavity may lie parallel one to the other or may diverge one from the other across the housing. Of course, the edges of the rotary or oscillatory valves conform to the edges of the openings through the housing.

Referring now to the embodiment hereof illustrated in FIGS. 13-15, fluid admission into the cavity is provided through one or both of the endwalls of the housing. Particularly, there is provided a shaft suitably journalled in bearings 152. The end face 154 of shaft 150 lies flush with the inner face of end wall 180. Shaft 150 has a central bore 156 in communication with a source of fluid pressure, not shown. An inclined passage 158 communicates with bore 156 and terminates in an opening 160 through end face 154 offset from the axis of shaft. 150. A suitable seal 161 is provided about shaft 150. Timing gears are provided and include a gear 162 carried on output shaft 200 in meshing engagement with a gear 164 fixed on shaft 150. The shaft 150 is located with respect to the cavity such that its central axis passes through a portion 166 of the housing radially outwardly of the cavity whereby, upon unidirectional rotation of shaft 150, the offset opening 160 sequentially registers with the cavity and the side wall of housing portion 166. Particularly, a seal 168 is provided on the lateral face of housing portion 166. When shaft 150 registers with portion 166, port 160 bears in sealing relation against seal 168. The port 160 may be elongated as at 170 to obtain the proper period of admission. It will be appreciated that the foregoing end wall admission valve can be utilized in conjunction with the end wall exhaust ports.

It will be appreciated that the timing mechanisms for each of the rotary valves illustrated in FIGS. 10-12 and FIGS. 13-15 is duplicated for each valve. That is, there is provided a gear driven from the output shaft for each valve utilized in a particular engine.

While the expansible fluid rotary engine has been described with respect to a two lobed chamber and a triangular rotor, it will be appreciated that the rotary engine hereof can be employed in a multi-lobed epitrochoidal housing mounting a rotor having one more side than the number of lobes. Particularly, the present invention can be employed with a three lobe epitrochoidal housing mounting a substantially square rotor. ln this and other configurations, exhaust valves are mounted on opposite sides of the cusps of the epitrochoidal chamber. Similar timing arrangements could be there employed, for example, utilizing a single camshaft for each valve or one camshaft for a pair of inlet and exhaust valves.

In use of the present invention, a closed cycle can be employed utilizing freon 12 as the expansible fluid. Expansible fluids such as hexafleurobenzine or freon 21 as well as other fluids which are expansible from a high to a low pressure such as steam can also be employed. Also, it will be appreciated that the present invention could be employed as a pump or blower, if desired.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. An expansible fluid engine comprising: a housing including an outer body defining a cavity and an axis, and inner body recieved within said outer body cavity and defining an axis, said housing including end walls on opposite sides of said cavity and said inner body, means including a shaft for mounting said inner body within said outer body cavity for relative rotation therein with the axis of said inner body being laterally spaced from and parallel to the axis of said outer body cavity and the axis of said shaft, said inner and outer bodies having respectively facing outer and inner peripheral surfaces defining a plurality of variable volume working chambers, the inner peripheral surfaces of said outer body cavity being multi-lobed with said lobes being equally spaced about the axis of said-outer body cavity, the outer peripheral surfaces of said inner body including a plurality of apex portions spaced circumferentially about the inner body and engageable with the inner peripheral surfaces of said outer body cavity to form seals between adjacent working chambers, said apex portions being one more in number than the number of said lobes, said mechanism including first and second passages for admitting fluid into first and second working chambers in said cavity, valves in said passages, each said valve including a member movable between positions opening and closing the corresponding passage to respectively admit fluid to the correponding working chamber and preclude fluid admission thereto, means for selectively moving each said'valve member between open and closed positions, said first and second valve members being carried by said outer body and opening through the inner surfaces of said first and second lobes respectively, each of said first and second members having an arcuate surface exposed to said cavity in the closed position thereof to permit the apex portions of said inner body to sweep past in sealing engagement therewith as said inner body rotates about said outer body cavity, timing means coupled to said moving means whereby the latter means is adapted to move said members from said open positions to said closed positions to permit said apex portions to sweep past the arcuate surfaces of said members, and means for exhausting fluid from said first and second working chambers including first and second exhaust ports respectively, each of said exhaust ports opening through one of said housing end walls.

2. A rotary mechanism according to claim 1 wherein said first and second valve members are mounted for oscillatory movement, said moving means being 3. A rotary mechanism according to claim 1 wherein said first and second valve members are mounted for unidirectional rotary movement said moving means being adapted to unidirectionally rotate said first and second members respectively between open and closed positions.

4. A rotary mechanism according to claim 1 wherein the arcuate surface on each of said first and second members has a radius different than the radius of the respective lobes at the location of the valves to permit the apex portion of said inner body to sweep past in continuous sealing engagement therewith as said inner body rotates about said outer body cavity, said moving means being adapted to continuously rotate said members to permit said apex portions to sweep past the arcuate surfaces of said members in continuous sealing engagement therewith.

5. A rotary mechanism according to claim 1 wherein said valves have a width less than the width of said inner body, a fixed guide surface adjacent each said valve member and forming a continuation of the shape of said lobes for guiding and supporting said inner body as the apex portions thereof sweep past said members.

6. A rotary mechanism utilizing an expansible fluid comprising: an outer body having a cavity, an inner body received within said outer body cavity, means including a shaft for mounting said inner body within said outer body cavity for relative rotation therein with the axis of said inner body being laterally spaced from and parallel to the axis of said outer body cavity and said shaft, said inner and outer bodies having respectively facing outer and inner peripheral surfaces defining a plurality of variable volume working chambers, the

' inner peripheral surfaces of said outer body cavity having a multi-lobed epitrochoidal shape with said lobes being equally spaced about the axis of said outer body adapted to oscillate said first and second members respectively between open and closed positions.

cavity, the outer peripheral surfaces of said inner body including a plurality of apex portions spaced circumferentially about the inner body and engageable with the inner peripheral surfaces of said outer body cavity to form seals between adjacent working chambers, said apex portions being one more in number than the number of said lobes, first and second valves carried by said outer body and spaced one from the other about the inner surface of said outer body cavity, said valves opening through the inner peripheral surface of said -outer body into said cavity, each of said valves including a member movable between open and closed positions to provide communication therethrough with said cavity in said valve open position, each of said members in said closed position having an arcuate surface, the apex portions of said inner body being in continuous-sealing engagement with said arcuate surfaces as said apex seals sweep past said valve members, means for supplying the fluid to said first and second valves for admission into said working chambers when said first and second members lie in their open positions, timing means for selectively moving said first and seond members between said open and closed positions, means for exhausting fluid from said chambers, and guide means located at like circumferential positions about said outer body as said first and second valves and having a circumferential extent greater than the circumferential extent of said valve openings through the inner peripheral surface of said outer body cavity, said guide means forming a continuation of the epitrochoidal shape of the lobes of the inner surface of said outer body for supporting said apex seals as they sweep past said first and second valve members.

7. A rotary mechanism according to claim 6 wherein said valve members are mounted for oscillatory movement, said timing means being adapted to oscillate said members between open and closed positions.

8. A rotary mechanism according to claim 6 wherein said valve members are mounted for unidirectional rotary movement, said timing means being adapted to unidirectionally rotate said members between open and closed positions.

9. A rotary mechanism utilizing an expansible fluid comprising: an outer body having a cavity, an inner body received within said outer body cavity, means including a shaft for mounting said inner body within said outer body cavity for relative roation therein with the axis of said inner body being laterally spaced from and parallel to the axis of said outer body cavity and said shaft, said inner and outer bodies having respectively facing outer and inner peripheral surfaces defining a plurality of variable volume working chambers, the inner peripheral surfaces of said outer body cavity having a multi-lobed epitrochoidal shape with said lobes being equally spaced about the axis of said outer body cavity, the outer peripheral surfaces of said inner body including a plurality of apex portions spaced circumferentially about the inner body and engageable with the inner peripheral surfaces of said outer body cavity to form seals between adjacent working chambers, said apex portions being one more in number than the number of said lobes, first and second valves carried by said outer body and spaced one from the other about the inner surface of said outer body cavity, said valves opening through the inner peripheral surface of said outer body into said cavity, each of said valves including a member unidirectionally rotatable between open and closed positions to provide communication therethrough with said cavity in said valve open position, each of said members in said closed position having an arcuate surface, means for supplying the fluid to said first and second valves for admission into said working chambers when said first and second members lie in their open positions, timing means for continuously rotating said first and second members between open and closed positions such that the apex portions of said inner body lie in continuous sealing engagement with said arcuate surfaces as said apex seals sweep past said valve members, and means for exhausting the fluid from said chambers.

10. A rotary mechanism according to claim 9 including a secondary inlet valve spaced about the periphery of said outer body cavity from said first inlet valve and including a member movable between open and closed positions to provide communication therethrough with said cavity in said valve open position, said secondary inlet valve member in said closed position having a surface forming a continuation of the epitrochoidal shape of the associated lobe of the inner surface of said outer body to permit the apex portions of said inner body to sweep past in sealing engagement therewith as said inner body rotates about the outer body cavity, means for supplying expansible fluid under pressure to said first valve and expansible fluid under a pressure lower than the pressure of the fluid supplied to said first inlet valve to said secondary valve for admission of the lower pressure fluid into said working chambers when said secondary inlet valve lies in said open position, said secondary inlet valve being operable to admit the lower pressure fluid into the working chambers supplied with fluid through said first inlet valve after said first inlet valve has moved to a closed position.

11. A mechanism according to claim 10 wherein said inlet valves are spaced about the surface of one of said lobes.

12. A mechanism according to claim 11 wherein said first and second valves are spaced about the surface of one of said lobes, third and fourth valves spaced one from the other about the surface of a second lobe and opening through the surface thereof into said cavity, each of said third and fourth valves including a member movable between open and closed positions to provide communication therethrough with said cavity in said valve open position, each of said third and fourth members in said valve closed position having a surface conforming to said second lobe surface to permit the apex portions of said inner body to sweep past in sealing engagernent therewith as said inner body rotates about the outer body cavity, timing means and another secondary inlet valve spaced about the periphery of said second lobe from said third inlet valve and including a member movable between open and closed positions to provide communication therethrough with said cavity in said valve open position, means for supplying expan sible fluid under pressure to said third inlet valve for admission thereof into said working chambers when said third inlet valve lies in said open position, means for supplying expansible fluid under a pressure lower than the pressure of the fluid supplied to said third inlet valve to said other secondary valve for admission of the lower pressure fluid into said working chambers when said other secondary inlet valve lies in said open position, and timing means for selectivly moving said third and fourth members to said open position to respectively admit fluid into and exhaust the fluid from said chambers and to said valve closed position, said other secondary inlet valve being operable to admit the lower pressure fluid into the working chambers supplied with fluid through said third inlet valve after said third inlet valve has moved to a closed position.

13. A rotary mechanism utilizing a fluid comprising: a housing including an outer body defining a cavity and an axis, an inner body received within said outer body cavity and defining an axis, said housing including end walls on opposite sides of said cavity and said inner body, means including a shaft for mounting said inner body within said outer body cavity for relative rotation therein with the axis of said inner body being laterally spaced from and parallel to the axis of said outer body cavity and-the axis of said shaft, said inner and outer bodies having respectively facing outer and inner peripheral surfaces defining a plurality of variable volume working chambers, the inner peripheral surfaces of said outer body cavity being multi-lobcd with said lobes being equally spaced about the axis of said outer body cavity, the outer peripheral surfaces of saidinner body including a plurality of apex portions spaced circumferentially about the inner body and engageable with the inner peripheralsurfaces of said outer body cavity to form seals between adjacent working chambers, said apex portions being one more in number than the number of said lobes, said mechanism including a passage for admitting fluid into a working chamber in said cavity, a valve in said passage including a member movable between positions opening and closing said passage to respectively admit fluid to said working chamber and preclude fluid admission to said working chamber, means for selectively moving said member between said open position and said closed position, means for exhausting fluid from said working chamber including an exhaust port opening through one of said housing end walls, a second passage for admitting fluid into a second working chamber in said cavity, a second valve in said second passage including a member movable between positions opening and closing said second passage to respectively admit fluid to said second working chamber and preclude fluid admission to said second working chamber, means for selectively moving said second member between said open position and said closed position, means for exhausting fluid from said second working chamber including a second exhaust port opening through one of said hosuing end walls, said first valve and said first exhaust port being located to respectively admit fluid into and exhaust fluid from the cavity portion defined by a first one of said plurality of lobes, said second valve and said second exhaust port being located to respectively admit fluid to and exhaust fluid from the cavity portion defined by a second one of said plurality of lobes, said first and second valve members being mounted for unidirectional rotary movement, said first and second mentioned moving means being adapted to unidirectionally rotate said first and second members respectively between open and closed positions, said first and second valve members are carried by said outer body and open through the inner surfaces of said first and second lobes respectively, each of said first and second surfaces therewith. members including an arcuate surface having a radius different than the radius of the respective lobes at the location of the valves to permit the apex portion of said inner body to sweep past in continuous sealing engagement therewith as said inner body rotates about said outer body cavity, said moving means being adapted to continuously rotate said members to permit said apex portions to sweep past the arcuate surfaces of said members in continuous sealing engagement therewith.

14. A rotary mechanism utilizing a field comprising: a housing including an outer body defining a cavity and an axis, an inner body received within said outer body cavity and defining an axis, said housing including end walls on opposite sides of said cavity and said inner body, means including a shaft for mounting said inner body within said outer body cavity for relative rotation therein with the axis of said inner body being laterally spaced from and parallel to the axis of said outer body cavity and the axis of said shaft, said inner and outer bodies having respectively facing outer and inner peripheral surfaces defining a plurality of variable volume working chambers, the inner peripheral surfaces of said outer body cavity being multi-lobed with said lobes being equally spaced about the axis of said outer body cavity, the outer peripheral surfaces of said inner body including a plurality of apex portions spaced circumferentially about the inner body and engageable with the inner peripheral surfaces of said outer body cavity to form seals between adjacent working chambers, said apex portions being one more in number than the number of said lobes, said mechanism including a passage for admitting fluid into a working chamber in said cavity, a valve in said passage including a member movable between positions opening and closing said passage to respectively admit fluid to said working chamber and preclude fluid admission to said working chamber, means for selectively moving said member between said open position and said closed position, means for exhausting fluid from said working chamber including an exhaust port opening through one of said housing end walls, a second passage for admitting fluid into a second working chamber in said cavity, a second valve in said second passage including a member movable between positions opening and closing said second passage to respectively admit fluid to said second working chamber and preclude fluid admission to said second working chamber, means for selectively moving said second member between said open position and said closed position, means for exhausting fluid from said second working chamber including a second exhaust port opening through one of said housing end walls, said first valve and said first exhaust port being located to respectively admit fluid into and exhaust fluid from the cavity portion defined by a first one of said plurality of lobes, said second valve and said second exhaust port being located to respectively admit fluid to and exhaust fluid from the cavity portion defined by a second one of said plurality of lobes, said first and second valve members being carried by said outer body and opening through the inner surfaces of said first and second lobes respectively, said members including arcuate surfaces exposed to said cavity in the closed position thereof for sealing engagement with apex portions of said inner body as the latter sweeps past said arcuate surfaces, said valves having a width less than the width of said inner body, a fixed guide surface adjacent said valve members and forming a continuation of the epitrochoidal shape of said lobes for guiding and supporting said inner body as the apex portions thereof sweep past said members.

C 1, H l fl 1. LA I ll U1. (1Q HR if; E ION Patent No} 3 762 ,842 Dat d October 2 1973 Inventor(s) 7 lie C. George, Jr.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 5 line 66, "defined" should read -define--; .1 line 68 "surface" should read --surfaces-- Col. 7, line 47, rotor 23 should read rotor 24".

Col. 8, line 20, surfaces 66" should read --surfaces 66 form-; line 49, "sprockets 94" should read --sprockets 84" Col; 9, line 29, 'camschaft should read --camshaft-; line 47, "now" should read --not-, a

Col. 11-, line 63 "secure" should read -secured--,

Col. 12, line 63' "valve 43 I" should read --valve 421";

Col. 15; line 33-, "nosuing",should read --housing--.

Col. 20, line 59, claim 13 "saidinner" should read --said inner-.. I

Col. 17, line 18, claim 1, 'and" should read --an--; same line, "recieved" should read "received- Col. 21, line 17-, claim 13, 'hosuing' should read -housing--; line 32; claim 13, 'second surfaces therewith. should read "second".

$9 333 UNI'IED S'IA'IES PA'IEQI OFFICE CEH'IjIYFIC/MIE OF CORRECTION October 2 1973 Patent No. 3 a 762 Dated PAGE 2 Inventor(s) Leslie C. George, Jr.

It is certified that error appears in the abovei'dentified patent and that said Letters Patent are hereby corrected as shown below:

In Column 21, line 42, claim 14, "field" should read I --f].Llid"-. I v

Signed and sealed this 16th day of July 1971 (SEAL) Attest: v

MCCOY M. GIBSON; JR. 0. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. An expansible fluid engine comprising: a housing including an outer body defining a cavity and an axis, and inner body recieved within said outer body cavity and defining an axis, said housing including end walls on opposite sides of said cavity and said inner body, means including a shaft for mounting said inner body within said outer body cavity for relative rotation therein with the axis of said inner body being laterally spaced from and parallel to the axis of said outer body cavity and the axis of said shaft, said inner and outer bodies having respectively facing outer and inner peripheral surfaces defining a plurality of variable volume working chambers, the inner peripheral surfaces of said outer body cavity being multi-lobed with said lobes being equally spaced about the axis of said outer body cavity, the outer peripheral surfaces of said inner body including a plurality of apex portions spaced circumferentially about the inner body and engageable with the inner peripheral surfaces of said outer body cavity to form seals between adjacent working chambers, said apex portions being one more in number than the number of said lobes, said mechanism including first and second passages for admitting fluid into first and second working chambers in said cavity, valves in said passages, each said valve including a member movable between positions opening and closing the corresponding passage to respectively admit fluid to the correponding working chamber and preclude fluid admission thereto, means for selectively moving each said valve member between open and closed positions, said first and second valve members being carried by said outer body and opening through the inner surfaces of said first and second lobes respectively, each of said first and second members having an arcuate surface exposed to said cavity in the closed position thereof to permit the apex portions of said inner body to sweep past in sealing engagement therewith as said inner body rotates about said outer body cavity, timing means coupled to said moving means whereby the latter means is adapted to move said members from said open positions to said closed positions to permit said apex portions to sweep past the arcuate surfaces of said members, and means for exhausting fluid from said first and second working chambers including first and second exhaust ports respectively, each of said exhaust ports opening through one of said housing end walls.
 2. A rotary mechanism according to claim 1 wherein said first and second valve members are mounted for oscillatory movement, said moving means being adapted to oscillate said first and second members respectively between open and closed positions.
 3. A rotary mechanism according to claim 1 wherein said first and second valve members are mounted for unidirectional rotary movement, said moving means being adapted to unidirectionally rotate said first and second members respectively between open and closed positions.
 4. A rotary mechaniSm according to claim 1 wherein the arcuate surface on each of said first and second members has a radius different than the radius of the respective lobes at the location of the valves to permit the apex portion of said inner body to sweep past in continuous sealing engagement therewith as said inner body rotates about said outer body cavity, said moving means being adapted to continuously rotate said members to permit said apex portions to sweep past the arcuate surfaces of said members in continuous sealing engagement therewith.
 5. A rotary mechanism according to claim 1 wherein said valves have a width less than the width of said inner body, a fixed guide surface adjacent each said valve member and forming a continuation of the shape of said lobes for guiding and supporting said inner body as the apex portions thereof sweep past said members.
 6. A rotary mechanism utilizing an expansible fluid comprising: an outer body having a cavity, an inner body received within said outer body cavity, means including a shaft for mounting said inner body within said outer body cavity for relative rotation therein with the axis of said inner body being laterally spaced from and parallel to the axis of said outer body cavity and said shaft, said inner and outer bodies having respectively facing outer and inner peripheral surfaces defining a plurality of variable volume working chambers, the inner peripheral surfaces of said outer body cavity having a multi-lobed epitrochoidal shape with said lobes being equally spaced about the axis of said outer body cavity, the outer peripheral surfaces of said inner body including a plurality of apex portions spaced circumferentially about the inner body and engageable with the inner peripheral surfaces of said outer body cavity to form seals between adjacent working chambers, said apex portions being one more in number than the number of said lobes, first and second valves carried by said outer body and spaced one from the other about the inner surface of said outer body cavity, said valves opening through the inner peripheral surface of said outer body into said cavity, each of said valves including a member movable between open and closed positions to provide communication therethrough with said cavity in said valve open position, each of said members in said closed position having an arcuate surface, the apex portions of said inner body being in continuous sealing engagement with said arcuate surfaces as said apex seals sweep past said valve members, means for supplying the fluid to said first and second valves for admission into said working chambers when said first and second members lie in their open positions, timing means for selectively moving said first and seond members between said open and closed positions, means for exhausting fluid from said chambers, and guide means located at like circumferential positions about said outer body as said first and second valves and having a circumferential extent greater than the circumferential extent of said valve openings through the inner peripheral surface of said outer body cavity, said guide means forming a continuation of the epitrochoidal shape of the lobes of the inner surface of said outer body for supporting said apex seals as they sweep past said first and second valve members.
 7. A rotary mechanism according to claim 6 wherein said valve members are mounted for oscillatory movement, said timing means being adapted to oscillate said members between open and closed positions.
 8. A rotary mechanism according to claim 6 wherein said valve members are mounted for unidirectional rotary movement, said timing means being adapted to unidirectionally rotate said members between open and closed positions.
 9. A rotary mechanism utilizing an expansible fluid comprising: an outer body having a cavity, an inner body received within said outer body cavity, means including a shaft for mounting said inner body within said outer body cavity for relative roation therein with the axis of said Inner body being laterally spaced from and parallel to the axis of said outer body cavity and said shaft, said inner and outer bodies having respectively facing outer and inner peripheral surfaces defining a plurality of variable volume working chambers, the inner peripheral surfaces of said outer body cavity having a multi-lobed epitrochoidal shape with said lobes being equally spaced about the axis of said outer body cavity, the outer peripheral surfaces of said inner body including a plurality of apex portions spaced circumferentially about the inner body and engageable with the inner peripheral surfaces of said outer body cavity to form seals between adjacent working chambers, said apex portions being one more in number than the number of said lobes, first and second valves carried by said outer body and spaced one from the other about the inner surface of said outer body cavity, said valves opening through the inner peripheral surface of said outer body into said cavity, each of said valves including a member unidirectionally rotatable between open and closed positions to provide communication therethrough with said cavity in said valve open position, each of said members in said closed position having an arcuate surface, means for supplying the fluid to said first and second valves for admission into said working chambers when said first and second members lie in their open positions, timing means for continuously rotating said first and second members between open and closed positions such that the apex portions of said inner body lie in continuous sealing engagement with said arcuate surfaces as said apex seals sweep past said valve members, and means for exhausting the fluid from said chambers.
 10. A rotary mechanism according to claim 9 including a secondary inlet valve spaced about the periphery of said outer body cavity from said first inlet valve and including a member movable between open and closed positions to provide communication therethrough with said cavity in said valve open position, said secondary inlet valve member in said closed position having a surface forming a continuation of the epitrochoidal shape of the associated lobe of the inner surface of said outer body to permit the apex portions of said inner body to sweep past in sealing engagement therewith as said inner body rotates about the outer body cavity, means for supplying expansible fluid under pressure to said first valve and expansible fluid under a pressure lower than the pressure of the fluid supplied to said first inlet valve to said secondary valve for admission of the lower pressure fluid into said working chambers when said secondary inlet valve lies in said open position, said secondary inlet valve being operable to admit the lower pressure fluid into the working chambers supplied with fluid through said first inlet valve after said first inlet valve has moved to a closed position.
 11. A mechanism according to claim 10 wherein said inlet valves are spaced about the surface of one of said lobes.
 12. A mechanism according to claim 11 wherein said first and second valves are spaced about the surface of one of said lobes, third and fourth valves spaced one from the other about the surface of a second lobe and opening through the surface thereof into said cavity, each of said third and fourth valves including a member movable between open and closed positions to provide communication therethrough with said cavity in said valve open position, each of said third and fourth members in said valve closed position having a surface conforming to said second lobe surface to permit the apex portions of said inner body to sweep past in sealing engagement therewith as said inner body rotates about the outer body cavity, timing means and another secondary inlet valve spaced about the periphery of said second lobe from said third inlet valve and including a member movable between open and closed positions to provide communication therethrough with said cavity in said valve open position, meaNs for supplying expansible fluid under pressure to said third inlet valve for admission thereof into said working chambers when said third inlet valve lies in said open position, means for supplying expansible fluid under a pressure lower than the pressure of the fluid supplied to said third inlet valve to said other secondary valve for admission of the lower pressure fluid into said working chambers when said other secondary inlet valve lies in said open position, and timing means for selectively moving said third and fourth members to said open position to respectively admit fluid into and exhaust the fluid from said chambers and to said valve closed position, said other secondary inlet valve being operable to admit the lower pressure fluid into the working chambers supplied with fluid through said third inlet valve after said third inlet valve has moved to a closed position.
 13. A rotary mechanism utilizing a fluid comprising: a housing including an outer body defining a cavity and an axis, an inner body received within said outer body cavity and defining an axis, said housing including end walls on opposite sides of said cavity and said inner body, means including a shaft for mounting said inner body within said outer body cavity for relative rotation therein with the axis of said inner body being laterally spaced from and parallel to the axis of said outer body cavity and the axis of said shaft, said inner and outer bodies having respectively facing outer and inner peripheral surfaces defining a plurality of variable volume working chambers, the inner peripheral surfaces of said outer body cavity being multi-lobed with said lobes being equally spaced about the axis of said outer body cavity, the outer peripheral surfaces of said inner body including a plurality of apex portions spaced circumferentially about the inner body and engageable with the inner peripheral surfaces of said outer body cavity to form seals between adjacent working chambers, said apex portions being one more in number than the number of said lobes, said mechanism including a passage for admitting fluid into a working chamber in said cavity, a valve in said passage including a member movable between positions opening and closing said passage to respectively admit fluid to said working chamber and preclude fluid admission to said working chamber, means for selectively moving said member between said open position and said closed position, means for exhausting fluid from said working chamber including an exhaust port opening through one of said housing end walls, a second passage for admitting fluid into a second working chamber in said cavity, a second valve in said second passage including a member movable between positions opening and closing said second passage to respectively admit fluid to said second working chamber and preclude fluid admission to said second working chamber, means for selectively moving said second member between said open position and said closed position, means for exhausting fluid from said second working chamber including a second exhaust port opening through one of said hosuing end walls, said first valve and said first exhaust port being located to respectively admit fluid into and exhaust fluid from the cavity portion defined by a first one of said plurality of lobes, said second valve and said second exhaust port being located to respectively admit fluid to and exhaust fluid from the cavity portion defined by a second one of said plurality of lobes, said first and second valve members being mounted for unidirectional rotary movement, said first and second mentioned moving means being adapted to unidirectionally rotate said first and second members respectively between open and closed positions, said first and second valve members are carried by said outer body and open through the inner surfaces of said first and second lobes respectively, each of said first and second members including an arcuate surface having a radius different than the radius of thE respective lobes at the location of the valves to permit the apex portion of said inner body to sweep past in continuous sealing engagement therewith as said inner body rotates about said outer body cavity, said moving means being adapted to continuously rotate said members to permit said apex portions to sweep past the arcuate surfaces of said members in continuous sealing engagement therewith.
 14. A rotary mechanism utilizing a field comprising: a housing including an outer body defining a cavity and an axis, an inner body received within said outer body cavity and defining an axis, said housing including end walls on opposite sides of said cavity and said inner body, means including a shaft for mounting said inner body within said outer body cavity for relative rotation therein with the axis of said inner body being laterally spaced from and parallel to the axis of said outer body cavity and the axis of said shaft, said inner and outer bodies having respectively facing outer and inner peripheral surfaces defining a plurality of variable volume working chambers, the inner peripheral surfaces of said outer body cavity being multi-lobed with said lobes being equally spaced about the axis of said outer body cavity, the outer peripheral surfaces of said inner body including a plurality of apex portions spaced circumferentially about the inner body and engageable with the inner peripheral surfaces of said outer body cavity to form seals between adjacent working chambers, said apex portions being one more in number than the number of said lobes, said mechanism including a passage for admitting fluid into a working chamber in said cavity, a valve in said passage including a member movable between positions opening and closing said passage to respectively admit fluid to said working chamber and preclude fluid admission to said working chamber, means for selectively moving said member between said open position and said closed position, means for exhausting fluid from said working chamber including an exhaust port opening through one of said housing end walls, a second passage for admitting fluid into a second working chamber in said cavity, a second valve in said second passage including a member movable between positions opening and closing said second passage to respectively admit fluid to said second working chamber and preclude fluid admission to said second working chamber, means for selectively moving said second member between said open position and said closed position, means for exhausting fluid from said second working chamber including a second exhaust port opening through one of said housing end walls, said first valve and said first exhaust port being located to respectively admit fluid into and exhaust fluid from the cavity portion defined by a first one of said plurality of lobes, said second valve and said second exhaust port being located to respectively admit fluid to and exhaust fluid from the cavity portion defined by a second one of said plurality of lobes, said first and second valve members being carried by said outer body and opening through the inner surfaces of said first and second lobes respectively, said members including arcuate surfaces exposed to said cavity in the closed position thereof for sealing engagement with apex portions of said inner body as the latter sweeps past said arcuate surfaces, said valves having a width less than the width of said inner body, a fixed guide surface adjacent said valve members and forming a continuation of the epitrochoidal shape of said lobes for guiding and supporting said inner body as the apex portions thereof sweep past said members. 